Rotary tool including a collet

ABSTRACT

A collet for connecting a tool to a driver includes a shaft having an end. The collet includes a body including a first end that connects to the driver and a second end having an internal space partially defined by a frustoconical bore and a plurality of jaws disposed within the space. Each of the jaws includes a body having a frustoconical surface arranged to engage the frustoconical bore and an engagement member coupled to each body to move between an unlocked and a locked position. Rotation of the tool about the axis in a first direction biases the engagement member toward the unlocked position to allow movement of the tool with respect to the jaws, and rotation of the tool about the axis in a second direction opposite the first direction biases the engagement member toward the locked position wherein the tool is fixed with respect to the jaws.

RELATED APPLICATION DATA

This application is a continuation of U.S. patent application Ser. No.12/684,618 filed Jan. 8, 2010, the entire contents of which isincorporated herein by reference.

BACKGROUND

The present invention relates to a rotary tool for mounting tool bitsand bit replacements on rotatable drives such as drills, powerscrewdrivers, and other power tools. More particularly, the presentinvention relates to a quick connect collet that attaches tool bits andthe like to rotatable drives without the need for tools.

SUMMARY

In one embodiment, the invention provides a collet for connecting arotary tool to a rotary tool driver. The rotary tool includes a shafthaving a shaft end and a shaft diameter. The collet includes a bodyincluding a first end configured to connect to the rotary tool driverand a second end configured to receive the rotary tool. A magnet isdisposed within the body and is positioned to magnetically engage andcontact the shaft end to inhibit movement of the rotary tool along ashaft rotational axis. A support member is disposed within the body andis configured to support the shaft for rotation about the shaftrotational axis.

In another embodiment, the invention provides a collet for connecting arotary tool to a rotary tool driver. The rotary tool includes a shafthaving a shaft end and a shaft diameter. The collet includes a bodyincluding flats configured for engagement with a hand tool and knurledregions configured to improve a user's grip. The body also includes afirst end that includes threads that threadably engage a threaded shaftof the rotary tool driver, and a second end that includes an aperturehaving a diameter that is about the same as the shaft diameter such thatthe shaft fits within the aperture. A magnet is disposed within the bodyand is positioned to magnetically engage and contact the shaft end toinhibit movement of the rotary tool along a shaft rotational axis. Themagnet used in this embodiment is a rare earth magnet. A support memberincludes a one-way roller bearing that defines a bearing inside diameterthat is about the same as the shaft diameter such that the shaft fitswithin the inside diameter and is disposed within the body. The bearingis configured to support the shaft for rotation about the shaftrotational axis.

In another embodiment, the invention provides a rotary tool operable todrive a plurality of rotary tools. Each rotary tool includes a toolshaft having a tool end and a shaft diameter. The rotary tool includes ahousing including a driving end. A motor is supported within the housingand is operable to drive a shaft having a shaft end. A plurality ofcollets are each selectively connectable to the shaft end. Each of theplurality of collets includes a collet body including a first endthreadably connected to the shaft end and a second end including anaperture sized to receive the rotary tool shaft. A magnet is disposedwithin the collet body and is positioned to magnetically engage andcontact the tool end to inhibit movement of the rotary tool along a toolshaft rotational axis. A support member is disposed within the colletbody and is configured to support the tool shaft for rotation about therotational axis.

In another embodiment, the invention provides a collet for connecting arotary tool to a rotary tool driver. The rotary tool includes a shafthaving a shaft end and a shaft diameter. The collet includes a bodyincluding a first end that includes threads that threadably engage athreaded shaft of the rotary tool driver, and a second end that includesthree semi-circular indents forming an aperture. A magnet is disposedwithin the body and is positioned to magnetically engage and contact theshaft end to inhibit movement of the rotary tool along a shaftrotational axis. The magnet used in this embodiment is a rare earthmagnet. A shaft support member for this embodiment includes a spring, aspacer and a jaw and locking roller bearing assembly. The jaw andlocking roller bearing assembly defines a bearing inside diameter thatis about the same size in diameter as the shaft diameter, such that theshaft fits within the inside diameter and is disposed within the body.The jaw and locking roller bearing assembly is configured to support theshaft for rotation about the shaft rotational axis.

In another embodiment, the invention provides a collet and nose-capassembly for connecting a rotary tool to a rotary tool driver. Therotary tool includes a shaft having a shaft end and a shaft diameter.The collet and nose-cap assembly are adjustably fixed to the rotary tooldriver. The collet and nose-cap assembly includes a collet body having afirst end with castellated features configured for integrating with thenose-cap's recessed mating features, and a second end having an aperturefor receiving a rotary tool's shaft. The rotary tool driver includes ashaft with a threaded portion that extends through the nose-cap andconnects to the collet body. The collet body has a set of jaws that arepressed upon by the rotary tool driver shaft to secure the rotary toolshaft. The rotary tool shaft is secured by the set of jaws. The colletbody mates with the nose-cap and the nose-cap is tightened onto therotary tool driver shaft securing the rotary tool shaft within the setof jaws. The nose-cap has a body that has gripping sections to ease thetightening process without a tool.

In another construction, the invention provides a collet for connectinga rotary tool to a rotary tool driver, the rotary tool including a shafthaving a shaft end and a shaft diameter. The collet includes a bodyincluding a first end arranged to connect to the rotary tool driver anda second end having an internal space at least partially defined by afrustoconical bore and a plurality of jaws disposed at least partiallywithin the space. Each of the jaws includes a body having afrustoconical surface sized and arranged to engage the frustoconicalbore and an engagement member movably coupled to each body to movebetween an unlocked position and a locked position. Rotation of therotary tool about the shaft rotational axis in a first direction biasesthe engagement member toward the unlocked position to allow movement ofthe rotary tool with respect to the plurality of jaws, and rotation ofthe rotary tool about the shaft rotational axis in a second directionopposite the first direction biases the engagement member toward thelocked position wherein the rotary tool is substantially fixed withrespect to the plurality of jaws.

In still another construction, the invention provides a collet forconnecting a rotary tool to a rotary tool driver, the rotary toolincluding a shaft having a shaft end and a shaft diameter. The colletincludes a body including a first end arranged to connect to the rotarytool driver, a second end having an internal space at least partiallydefined by a frustoconical bore, and an axis extending between the firstend and the second end. A plurality of jaw bodies each having afrustoconical outermost surface is arranged to engage the frustoconicalbore. Each jaw body is movable along the axis between a retractedposition and an extended position, and the frustoconical surface and thefrustoconical bore cooperate to move each jaw body radially toward theaxis as the jaw body moves from the retracted position to the extendedposition. The collet includes a plurality of rollers with each rotatablycoupled to one of the jaw bodies and movable with respect to therespective jaw body between an unlocked position and a locked position.A biasing member is disposed within the space and is operable to biaseach of the plurality of jaw bodies toward the extended position,wherein rotation of the rotary tool about the axis in a first directionbiases each roller toward the unlocked position to allow movement of therotary tool with respect to the respective jaw body, and rotation of therotary tool about the axis in a second direction opposite the firstdirection biases each roller toward the locked position wherein therotary tool is substantially fixed with respect each of the jaw bodies.

In another construction, the invention provides a collet for connectinga rotary tool to a rotary tool driver, the rotary tool including a shafthaving a shaft end and a shaft diameter. The collet includes acylindrical surface defining a cylindrical space that surrounds an axis,a frustoconical surface extending from the cylindrical surface anddefining a frustoconical space, and a plurality of jaws positionedsubstantially within the frustoconical space. Each of the jaws ismovable along the axis between a retracted position and an extendedposition. A plurality of roller receiving spaces are each defined by thecooperation of a locking surface and an unlocking surface and are formedas part of one of the jaws. The collet also includes a plurality ofrollers, with each positioned within one of the roller receiving spacesand movable between an unlocked position in which the roller engages theunlocking surface and a locked position in which the roller engages thelocking surface. A biasing member is disposed within the cylindricalspace and is operable to bias each of the plurality of jaws toward theextended position, wherein rotation of the rotary tool about the axis ina first direction biases the roller toward the unlocked position toallow movement of the rotary tool with respect to the respective jaw,and rotation of the rotary tool about the axis in a second directionopposite the first direction biases the roller toward the lockedposition wherein the rotary tool is substantially fixed with respect toeach of the jaws.

Other features and advantages of the invention will become apparent tothose skilled in the art upon review of the following detaileddescription, claims, and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of a collet, a tool bit and a rotarydrive;

FIG. 2 is an exploded sectional view of a collet suitable for use in theassembly of FIG. 1;

FIG. 3 is a perspective view of the collet of FIG. 1 having a firstaperture diameter;

FIG. 4 is a perspective view of the collet of FIG. 1 having a secondaperture diameter;

FIG. 5 is a perspective view of the collet of FIG. 1 having a thirdaperture diameter;

FIG. 6 is an exploded sectional view of another collet suitable for usein the assembly of FIG. 1;

FIG. 7 is a side view of the collet of FIG. 6 with a the housing shownin phantom;

FIG. 8 is a top view of the collet of FIG. 6 with the housing removed;

FIG. 9 is a side view of another collet securing a bit while in aresting position, and with the housing shown in phantom;

FIG. 10 is a side view of the collet of FIG. 9 securing a bit with thehousing shown in phantom;

FIG. 11 is a perspective view of the collet of FIG. 9 coupled to arotary tool driver;

FIG. 12 a is a side view of the collet and rotary tool driver of FIG. 11showing the movement of a rotary tool driver chuck to engage the collet;

FIG. 12 b is a side view of the collet and rotary tool driver of FIG. 11showing the movement of a rotary tool driver chuck to tighten thecollet; and

FIG. 12 c is a side view of the collet and rotary tool driver of FIG. 11showing the movement of a rotary tool driver chuck to a disengaged oroperating position.

DETAILED DESCRIPTION

Before any embodiments of the invention are explained in detail, it isto be understood that the invention is not limited in its application tothe details of construction and the arrangement of components set forthin the following description or illustrated in the following drawings.The invention is capable of other embodiments and of being practiced orof being carried out in various ways. Also, it is to be understood thatthe phraseology and terminology used herein is for the purpose ofdescription and should not be regarded as limiting. The use of“including,” “comprising” or “having” and variations thereof herein ismeant to encompass the items listed thereafter and equivalents thereofas well as additional items. The order of limitations specified in anymethod claims does not imply that the steps or acts set forth thereinmust be performed in that order, unless an order is explicitly set forthin the specification.

FIG. 1 illustrates a collet 10 for connecting a rotary tool bit 14 to arotary tool driver 18. The rotary tool driver 18 can be a drill, poweredscrewdriver, or other rotatable power tools arranged to drive the rotarytool bit 14. The rotary tool driver 18 includes a housing 22, and amotor 26 disposed substantially within the housing 22. The rotor 34includes a stator 30 that is fixedly supported by the housing 22 toinhibit rotation of the stator 30 with respect to the housing 22. Therotor 34 is positioned adjacent the stator 30 and is supported forrotation with respect to the stator 30 and in response to the flow ofelectrical power to the stator 30 and/or rotor 34. In preferredconstructions, the rotor 34 is substantially cylindrical and fits withina cylindrical space defined by the stator 30. In other constructions,the rotor 34 is positioned outside of the stator 30 or is spaced axiallyfrom the stator 30.

The rotary tool driver 18 can be powered by an AC motor 26 connected toan AC power source 38 such as is shown in FIG. 1. Alternatively, therotary tool driver 18 can be powered by a DC Motor connected tobatteries.

The rotor 34 includes a tool driver shaft 42 that extends along therotational axis 35 of the rotor 34. The tool driver shaft 42 providespoints for rotational support of the rotor 34. In the illustratedconstruction, the tool driver shaft 42 extends from the housing 22 andincludes a threaded portion 46 that receives the collet 10. In otherconstructions, the tool driver shaft 42 provides input to a gear box orother speed changing arrangement (increasing or decreasing). An outputshaft extends from the gear box or speed changing device and out of thehousing 22. In these constructions, the output shaft also includes athreaded portion 46 that receives the collet 10. As would be understoodby one of ordinary skill in the art, the arrangement used to drive thetool driver shaft 42 is not critical to the invention so long as theshaft extends from the housing and can receive the collet 10.

A portion of the rotary tool bit 14 is illustrated in FIG. 1. The rotarytool bit 14 includes a shank portion 50 and a cutting portion 54attached to or formed out of the shank portion 50. The cutting portion54 could include flutes that allow for the boring of an accurately sizedbore or for other functions as desired. Thus, any tool that isrotationally driven to cut a workpiece or to function could be therotary tool bit 14. Generally, the shank portion 50 is cylindrical andhas a standard rotary tool diameter. For example, many rotary tools areformed with ⅛ inch (3 mm) diameters while others might be formed with ¼inch (6 mm) or ⅜ inch (9 mm) diameters. In some constructions, the shankportion 50 includes two or more flats that can aid in connecting theshank portion 50 to a chuck.

As illustrated in FIG. 2, the collet 10 includes a body 58, an axialrestraining member 62 and a radial support member 66. The collet body 58includes a restraining member space 70, a first end 74, a second end 78,flats 82, and knurled regions 86. The first end 74 is threaded andconfigured to threadably engage the threaded portion 46 of the rotarytool 18. In this embodiment, the collet 10 and the tool driver shaft 42are threaded. Alternatively, the collet 10 and the tool driver shaft 42can be connected by welds, adhesives, a cam mechanism, friction fitting,fastener, and any other suitable coupling means. Thus, the first end 74can be configured differently to facilitate connection to the tooldriver shaft 42.

The second end 78 has an opening (aperture) 90 for receiving tool bits14, such as screw bits, chisel bits, drill bits (like the oneillustrated in FIG. 1), and any other tool bit 14 that can be used witha rotatable power tool 18.

The flats 82 are arranged in pairs that oppose one another such that thetwo flats 82 in any pair are substantially parallel to one another. Theflats 82 are configured for engagement with a hand tool such asdifferent types of wrenches, and pliers. The hand tool engages thecollet 10 by grasping the flats 82. The user then turns the hand tool inan effort to secure the connection between the collet 10 and the rotarytool driver 18 or to disconnect the collet 10 from the rotary tooldriver 18.

The knurled regions 86 are configured to improve a users grip on thecollet 10. When a user grips the collet 10 the knurled regions 86provide increased friction, thereby allowing a user to install or removethe collet 10 by hand. In the illustrated construction there are twoknurled regions 86 with a non-knurled region separating the two. Ofcourse, other arrangements are also possible.

FIG. 2 illustrates an exploded sectional view of the collet 10 to betterillustrate the internal components. The collet body 58 includes aninterior opening that includes various sized areas. As discussed, thefirst end 74 includes threads sized and arranged to threadably engagethe threaded portion 46 of the tool driver shaft 42. Moving toward thesecond end 78, the next space adjacent the threaded portion is therestraining member space 70. The restraining member space 70 includes acylindrical bore sized to receive the axial restraining member 62. Insome constructions, the restraining member space 70 includes a featurethat restrains or aids in restraining the axial restraining member 62 inthe desired position. For example, one construction provides a narrowslot sized to receive a snap ring. Once positioned, the snap ringinhibits axial movement of the axial restraining member 62 out of thebody 58 through the first end 74. In still other constructions, theaxial restraining member 62 is held in place by the threaded end 46 ofthe rotary tool driver 18.

The space adjacent the restraining member space 70 is a cylindricalshaft receiving space 94. The shaft receiving space 94 includes acylindrical bore sized to receive the shank portion 50 of the rotarytool bit 14. An end of the shaft receiving space 94, closest to thefirst end 74, is abutted by the axial restraining member 62 and/or therestraining member space 70.

The space adjacent the shaft receiving space 94 is a radial restrainingmember space 98. The radial restraining member space 98 includes acylindrical bore sized to receive the radial support member 66.

Near the second end 78 and in the space adjacent the opening 90 is asecond shaft receiving space 102. The second shaft receiving space 102includes a cylindrical bore sized to receive the shank portion 50 of therotary tool bit 14.

The axial restraining member 62 includes a magnet 103 sized to bedisposed inside of the restraining member receiving space 70. The magnet103 is cylindrical in shape with two flat portions designated to be atop and a bottom. The magnet 103 is configured to magnetically engagethe shank portion 50 of the rotary tool bit 14 and restrict axialmovement toward the second end 78. In preferred embodiments, the magnet103 is made of rare earths to increase the magnetic engagement betweenthe magnet 103 and the shank portion 50.

The radial support member 66 includes a roller bearing assemblypositioned within the collet body 58. In preferred construction, theroller bearing is a one-way locking roller bearing that includes aplurality of rollers 114 supported by a roller cage 110 such that therollers 114 are substantially free to rotate in a first direction butare inhibited from rotating in an opposite direction. The rollers 114are positioned to define a bearing inside diameter 106 that is aboutequal to the diameter of the tool bit 14 intended to be received by thecollet 10. In other constructions, other types of one-way bearings maybe employed. For example, one-way needle bearings, ball bearings, andthe like could be employed in place of or in conjunction with the rollerbearing assembly.

FIGS. 3, 4, and 5 illustrate three collet bodies 10 a, 10 b, 10 carranged to receive three different sized tool bits 14. As can be seen,the apertures 90 a, 90 b, 90 c are each sized to receive a particularsize tool bit 14. Each of the collet bodies 58 a, 58 b, 58 c issubstantially the same with the exception of the apertures 90 a, 90 b,90 c. In addition to the apertures 90 a, 90 b, 90 c, each of the one-waylocking roller bearings 66 define an inside diameter 106 thatcorresponds to the particular tool bit 14 being received.

In operation, the collet 10 is threaded on to the end of the tool drivershaft 42. A wrench or another type of hand tool, capable of gripping theflats 82 located on the collet body 58, can be used to tighten thecollet 10 onto the end of the tool driver shaft 42. Alternatively, thecollet 10 can be hand tightened onto the driver shaft 42. Once thecollet 10 is secured onto the tool driver shaft 42 a rotary tool bit 14can be placed into the collet 10. A rotary tool bit 14 is pushed intothe aperture 90 on top of the collet 10 until it contacts the magnet103. The magnet 103 inhibits further insertion and provides magneticresistance to the axial removal of the rotary tool bit 14. The one-waylocking roller bearings 66 provide mechanical resistance to radialmovement of the tool bit 14 and also inhibit rotation of the tool bit 14in one direction. As the motor rotates the collet 10, the tool bit 14rotates with the collet 10 and performs the desired work.

FIG. 6 illustrates another construction of a collet 120 that includes abody 124 having an exterior that is similar to the exterior of thecollet 10 of FIGS. 1-5. Specifically, the body 124 includes a first end74 and a second end 78 similar to those of the collet of FIGS. 1-5. Thebody 124 also includes flats 82 and knurled portions 86 similar to thoseof the collet of FIGS. 1-5.

Unlike the body 58 of FIGS. 1-5 which includes a single interior spacethat extends from the first end 74 to the second end 78, the body 124 ofFIG. 6 includes two separate interior spaces. A first space 128 isthreaded, much like the threaded portion of the body 58 to receive therotary tool shaft 42. As with the threaded portion of the body 58, otherconstructions may use different (non-threaded) arrangements in the firstspace 128 to connect the collet 120 to a differently-arranged shaft 42.

A second space 132 includes a first bore 136 that is substantiallycylindrical and includes a flat or blind end. The first bore 136 has adiameter that closely matches the diameter of the tool bit 14 intendedto be held in the collet 120.

A second bore 140 is positioned adjacent the first bore 136 on the sideopposite the first end 74. The second bore 140 has a diameter that islarger than the diameter of the first bore 136. The second bore 140 hasan axial length and a diameter sized to accommodate a radial supportmember 144.

A third bore 148 includes a substantially cylindrical portion 149 and anenlarged slot portion 150. The cylindrical portion 149 includes adiameter similar to that of the first bore 136. The slot portion 150 isformed in the cylindrical portion 149 and is sized to receive an axialrestraining member 152.

The radial support member 144 is similar to the radial support member 66of the collet 10 of FIGS. 1-5. The radial support member 144 includesseveral roller bearings 156 each held within a cage that is sized to fitwithin the second bore 140. The roller bearings 156 are preferablysupported such that they are free to rotate in a first direction butinhibited from rotating in a second direction. The roller bearings 156cooperate to define an inside diameter that is about equal to thediameter of the rotary tool bit 14 which the collet 120 is intended tosupport. It should be noted that other constructions could include otherbearings such as ball, journal, needle, etc. so long as the bearingsupports the rotary tool 14 in a way that inhibits free rotation in atleast one direction.

The axial restraining member 152 is positioned adjacent the second end78 of the body 124 within the enlarged slot portion 150. The axialrestraining member 152 illustrated in FIG. 6 includes a canted coil 158.The canted coil 158 is a spring made with slanted or angled coils. Thecanted coil 158 displaces to allow for the insertion of the rotary toolbit 14 but provides resistance to the removal of the tool 14. Theresistance is about proportional to the amount of displacement realizedby the canted coils when the tool bit 14 is inserted.

To use the collet 120 of FIG. 6, a user first threadably engages thedesired collet 120 to the rotary tool driver 18. To insert a rotary toolbit 14 into the collet 120, the user simply inserts the cylindrical endof the rotary tool bit 14 into the opening 90 of the second end 78. Therotary tool bit 14 contacts the axial restraining member 152 to deflectthe canted coils. The rotary tool bit 14 passes through the radialsupport member 144 and into the first bore 136 where the tool bit 14eventually contacts the bottom, thereby inhibiting further insertion.The radial support member 144 inhibits radial movement of the tool bit14 and also engages the tool bit 14 to couple the collet 120 and thetool bit 14 for rotation, thereby allowing the tool bit 14 to performthe desired work. The axial restraining member 152 provides resistanceto axial extraction of the tool bit 14 to inhibit the unwanted removalof the tool bit 14 from the collet 120.

FIGS. 7 and 8 illustrate another construction of a collet 172 thatincludes a chuck 195, an axial retaining member 236, and an actuatorassembly 200 inside a collet body 176. The collet body 176 includesknurled portions and can include flats as have been described withregard to the collets 10, 120 of FIGS. 1-6. The collet 172 illustratedin FIG. 7 includes a first end 74 arranged to attach to the drivingshaft 42. As with other constructions, other arrangements could beemployed to attach the collet 172 to the shaft 42.

The collet body 176 includes a second open end 78 that includes afrustoconical portion 180 and a cylindrical portion 184. Thefrustoconical portion 180 includes a frustoconical bore that includes asmall diameter end 188 near the second end 78 and a wide or largediameter portion 192 toward the first end 74. The cylindrical portion184 includes a cylindrical bore that extends from the large diameter end192 of the frustoconical bore to a planar bottom surface 194 near thefirst end 74.

The actuator assembly 200 is disposed at least partially within thecylindrical portion 184 and includes a biasing member 232 and a spacer228. In the illustrated construction, the biasing member 232 includes acoil spring 237 that biases the spacer 228 in a direction away from theplanar bottom surface 194 of the cylindrical portion 184 (i.e., towardthe second end 78). In other constructions, other biasing members 232are employed. For example, one construction employs Belleville washersthat cooperate to define a Belleville spring.

The spacer 228 includes a disk shaped annular member that includes abottom surface and a top surface. The spacer 228 includes a central borethat is sized to allow the passage of the desired tool bit 14. In someconstructions, a skirt extends downward around the bottom surface toreceive a portion of the biasing member 232 to assure that the biasingmember 232 does not slip with respect to the spacer 228. In preferredconstructions, the top surface of the spacer is planar.

The axial restraining member 236 includes a magnet 238 similar to thatdescribed with regard to the collet 10 of FIGS. 1-5. Thus, the magnet238 could be a rare earth magnet. The magnet 238 is positioned at thebottom of the cylindrical portion 184 and is surrounded by the biasingmember 232.

The chuck 195 includes a number of jaws 196 arranged within thefrustoconical portion 180 of the collet body 176. In the illustratedconstruction, three jaws 196 are employed with other constructionsincluding more jaws 196 or fewer jaws 196. Each jaw 196 includes a body240 having a frustoconical outer surface 245, a substantially planar topsurface 250, and a substantially planar bottom surface 255. Thefrustoconical outer surface 245 is tapered at an angle similar to thatof the frustoconical portion of the collet body 176.

Turning to FIG. 8, each jaw 196 also includes an interior opening 260and a roller 265 positioned within the opening 260. The opening 260includes a first curved side 270 and a second hooked side 275. Duringrotation in a first direction (clockwise in FIG. 8) the rollers 265shift toward the curved side 270 and allow free rotation of the roller265 and the tool bit 14. During rotation in the opposite direction(counterclockwise in FIG. 8) the rollers 265 shift toward the secondhooked side 275. In this position, the roller 265 wedges within thehooked side 275, is not free to rotate, and is displaced outwardslightly. Thus, the rollers 265 do not allow movement of the tool bit 14with respect to the collet 172. Thus, the single rollers 265 within eachjaw 196 act as one way bearings.

To use the collet 172, the user first threadably engages the desiredcollet 172 to the rotary tool driver 18. The jaws 196 are then pusheddownward toward the first end 74 to compress the biasing member 232 andallow the jaws 196 to separate. The tool bit 14 is inserted into thespace between the jaws 196, passes through the central aperture of thespacer 228, and contacts the axial restraining member 236. When the userreleases the jaws 196, the biasing member 232 displaces upward to movethe spacer 228 toward the second end 78. As the spacer 228 moves, thejaws 196, which sit on top of the spacer 228 are forced upward. Thefrustoconical outer surfaces 245 of the jaws 196 interact with thefrustoconical surface of the collet body 176 to move the jaws 196 inwardas they move upward. Eventually, the rollers 265 contact the tool bit 14and the upward movement stops. The biasing member 232 is selected toassure that enough residual force is available to firmly grasp the toolbit 14 between the jaws 196 of the chuck 195. Thus, the construction ofFIGS. 7 and 8 is able to hold tool bits 14 having different diameters.

FIGS. 9-12 c illustrate another construction of a collet 280 thatoperates with a chuck 285 of the power tool 18 to quickly engage arotary tool bit 14. With reference to FIGS. 9 and 10, the collet 280includes a body 290 that has an outer surface 295 and an inner space300, a shaft 305, and a plurality of jaws 310. The jaws 310 are similarto the jaws 196 of the construction of FIGS. 7 and 8.

The shaft 305 includes a first portion 315 that is configured to engagethe chuck 285 of the power tool 18. In the illustrated construction, thefirst portion 315 of the shaft 305 is cylindrical with other shapesbeing possible. For example, in some constructions a polygonal shaft isemployed to improve the connection between the power tool 18 and theshaft 305. A second portion 320 of the shaft 305 includes a threadedportion 325 and a substantially planar end 330.

The outer surface 295 includes a cylindrical portion 335 and afrustoconical portion 340. The cylindrical portion 335 may includeknurled regions or flats to improve the users grip on the body 290 tofacilitate rotation of the body 290. As illustrated in FIG. 11, an endof the cylindrical portion 335 away from the frustoconical portion 340includes castellated features 345. The castellated features 345 includea plurality of rectangular extensions separated by a plurality ofrectangular gaps. In preferred constructions, the rectangular gaps areabout the same size as the rectangular extensions. However, other sizedgaps could also be employed if desired.

The inner space 300 includes a frustoconical space 350 and a threadedspace 355. The threaded space 355 threadably engages the threadedportion 325 of the shaft 305 such that rotation of the body 290 movesthe body 290 axially along the shaft 305. The frustoconical space 350includes a tapered frustoconical surface 360 that is largest near thethreaded portion 325 and smallest at an open end 365. The jaws 310 arepositioned within the space 350 adjacent the frustoconical surface 360and are free to move axially between the threaded space 355 and the openend 365.

In use, the collet 280 can receive various rotary tools 14 having arange of shaft diameters. When no rotary tool shaft is positioned in thecollet 280, the jaws 310 are free to move toward the threaded portion325 to leave the largest available opening diameter. The rotary toolshaft 14 is inserted into the space between the jaws 310 until therotary tool shaft 14 contacts the end 330 of the shaft 305. The body 290is then rotated. The engaged threaded portions 325 355 act to move thebody 290 toward the power tool 18, thereby reducing the space betweenthe threaded portion 325 and the opening 365. The reduced space forcesthe jaws 310 toward the smaller end of the frustoconical space 350 whichforces the jaws 310 closer together until they clamp the rotary toolshaft 14 as described with regard to the construction of FIGS. 7 and 8.In some constructions, a biasing member such as a coil spring ispositioned between the jaws 310 and the threaded space 355 to bias thejaws 310 toward the small end 365 of the frustoconical portion 340.

The castellated features 345 can be used to aid the user in tighteningor loosening the body 290. As illustrated in FIG. 11, the power tool 18includes corresponding castellated features 370 arranged to receive thecastellated features 345 of the body 290. As illustrated in FIG. 12 a,the user can move a 285 housing of the power tool 18 toward the body 290to engage the castellated features 345, 370 as illustrated in FIG. 12 b.The user than rotates the chuck 285 to tighten the body 290. The largersize and enhanced gripping features of the chuck 285 allow the user tobetter tighten and more easily loosen the body 290 as desired. Oncetightening or loosening is completed, the user disengages thecastellated features 345, 370 as illustrated in FIG. 12 c.

In preferred constructions, the chuck 285 is biased toward thedisengaged position and automatically returns to that position when theuser releases the chuck 285. In other constructions, the body 290includes a movable portion that moves into engagement with the chuck285. The movable portion could be biased to the disengaged position ifdesired.

Various other features and advantages of the invention are set forth inthe following claims.

What is claimed is:
 1. A collet for connecting a rotary tool to a rotarytool driver, the rotary tool including a shaft having a shaft end and ashaft diameter, the collet comprising: a body including a first endarranged to connect to the rotary tool driver and a second end having aninternal space at least partially defined by a frustoconical bore; aplurality of jaws disposed at least partially within the space, each ofthe jaws including a body having a frustoconical surface sized andarranged to engage the frustoconical bore and an engagement membermovably coupled to each body to move between an unlocked position and alocked position, wherein rotation of the rotary tool about the shaftrotational axis in a first direction biases the engagement member towardthe unlocked position to allow movement of the rotary tool with respectto the plurality of jaws, and rotation of the rotary tool about theshaft rotational axis in a second direction opposite the first directionbiases the engagement member toward the locked position wherein therotary tool is substantially fixed with respect to the plurality ofjaws.
 2. The collet of claim 1, wherein the first end includes threadsarranged to threadably engage the rotary tool driver.
 3. The collet ofclaim 1, wherein the internal space includes a cylindrical portion and afrustoconical portion defined by the frustoconical bore.
 4. The colletof claim 3, further comprising a magnet disposed within the cylindricalportion and operable to engage the shaft end of the rotary tool.
 5. Thecollet of claim 1, wherein the frustoconical surface of each bodyincludes a partial cylindrical surface that is tapered.
 6. The collet ofclaim 1, wherein each engagement member includes a cylindrical roller.7. The collet of claim 6, wherein each body includes an aperture definedby the cooperation of a locking surface and an unlocking surface, theaperture sized to movably receive one of the rollers therein.
 8. Thecollet of claim 7, wherein each of the rollers is in engagement with thelocking surface when the engagement member is in the locked position andis in engagement with the unlocking surface when the engagement memberis in the unlocked position.
 9. The collet of claim 1, wherein each ofthe plurality of jaws is movable along the axis between an extendedposition in which each of the engagement members is a first distancefrom the axis and a retracted position in which each of the engagementmembers is a second distance from the axis, the second distance beinggreater than the first distance, the collet further comprising a biasingmember positioned within the space and operable to bias each of theplurality of jaws toward the extended position.
 10. The collet of claim9, further comprising a spacer positioned between the biasing member andthe plurality of jaws.
 11. A collet for connecting a rotary tool to arotary tool driver, the rotary tool including a shaft having a shaft endand a shaft diameter, the collet comprising: a body including a firstend arranged to connect to the rotary tool driver, a second end havingan internal space at least partially defined by a frustoconical bore,and an axis extending between the first end and the second end; aplurality of jaw bodies each having a frustoconical outermost surfacearranged to engage the frustoconical bore, each jaw body movable alongthe axis between a retracted position and an extended position, andwherein the frustoconical surface and the frustoconical bore cooperateto move each jaw body radially toward the axis as the jaw body movesfrom the retracted position to the extended position; a plurality ofrollers each rotatably coupled to one of the jaw bodies and movable withrespect to the respective jaw body between an unlocked position and alocked position; a biasing member disposed within the space and operableto bias each of the plurality of jaw bodies toward the extendedposition, wherein rotation of the rotary tool about the axis in a firstdirection biases each roller toward the unlocked position to allowmovement of the rotary tool with respect to the respective jaw body, androtation of the rotary tool about the axis in a second directionopposite the first direction biases each roller toward the lockedposition wherein the rotary tool is substantially fixed with respecteach of the jaw bodies.
 12. The collet of claim 11, wherein the firstend includes threads arranged to threadably engage the rotary tooldriver.
 13. The collet of claim 11, wherein the internal space includesa cylindrical portion and a frustoconical portion defined by thefrustoconical bore.
 14. The collet of claim 13, further comprising amagnet disposed within the cylindrical portion and operable to engagethe shaft end of the rotary tool.
 15. The collet of claim 11, whereinthe frustoconical surface of each jaw body includes a partialcylindrical surface that is tapered.
 16. The collet of claim 11, whereineach jaw body includes an aperture defined by the cooperation of alocking surface and an unlocking surface, the aperture sized to movablyreceive one of the rollers therein.
 17. The collet of claim 16, whereineach of the rollers is in engagement with the locking surface when theengagement member is in the locked position and is in engagement withthe unlocking surface when the engagement member is in the unlockedposition.
 18. The collet of claim 11, further comprising a spacerpositioned between the biasing member and the plurality of jaw bodies.19. A collet for connecting a rotary tool to a rotary tool driver, therotary tool including a shaft having a shaft end and a shaft diameter,the collet comprising: a cylindrical surface defining a cylindricalspace that surrounds an axis; a frustoconical surface extending from thecylindrical surface and defining a frustoconical space; a plurality ofjaws positioned substantially within the frustoconical space, each ofthe jaws movable along the axis between a retracted position and anextended position; a plurality of roller receiving spaces each definedby the cooperation of a locking surface and an unlocking surface formedas part of one of the jaws; a plurality of rollers, each positionedwithin one of the roller receiving spaces and movable between anunlocked position in which the roller engages the unlocking surface anda locked position in which the roller engages the locking surface; and abiasing member disposed within the cylindrical space and operable tobias each of the plurality of jaws toward the extended position, whereinrotation of the rotary tool about the axis in a first direction biasesthe roller toward the unlocked position to allow movement of the rotarytool with respect to the respective jaw, and rotation of the rotary toolabout the axis in a second direction opposite the first direction biasesthe roller toward the locked position wherein the rotary tool issubstantially fixed with respect to each of the jaws.
 20. The collet ofclaim 19, further comprising a magnet disposed within the cylindricalspace and operable to engage the shaft end of the rotary tool.